Calculating CPAP Run Time on Battery
If you suffer from Sleep Apena, your doctor would have suggested the use of a CPAP machine since it is the best non-surgical cure currently available. If you do use the CPAP you may be under the impression that you have no freedom from the machine and that you will be forced to give up activities such as camping.
But fear not, if you plan on using your CPAP while camping or while away from a power source, you will have to make use of a battery to power your machine. As they say knowledge is power, therefore if you know the run time which your battery will provide to your CPAP you will be able to plan your trip accordingly.
A complete Portable CPAP battery pack with the battery, charger and carrying case
How to find out how long you’re CPAP will run On a Particular Battery Type?
Well the scientific way to exactly find out how long your CPAP will run is a bit complicated. Here a layman’s explanation will be provided.
To start with, your CPAP machine will draw a certain amount of power when it is used continuously. This is commonly expressed in terms of Amp Hours which is simply the number of Amp’s of power which your CPAP consumes to run for one hour. Once you calculate of find the specific Amp/hr value of your CPAP unit, the rest is simple. Simply compare the Ah (Amp/hr) of your machine with the Ah of your battery; this is easy since batteries are usually rated with the same unit. Thus theoretically speaking if you purchase a 90Ah battery and your CPAP machine consumes 1Ah, you will get around 90 hours of use from your battery. This is one of the easiest ways to approximate the amount of power which you will get. However do understand that the above method is not scientific, since variance in the machine and electrical characteristics will exist. So it would be better if you add .3Ah to your CPAP machines power draw. This will act as a cushion and prevent you from forcibly waking up early in the morning because your CPAP shut down.